(February 23, 2021, 10:48 AM EST) -- WASHINGTON, D.C. — The U.S. Environmental Protection Agency on Feb. 22 released a pre-publication version of its Unregulated Contaminant Monitoring Rule (UCMR 5) for Public Water Systems, which proposes a rule requiring public water systems serving 3,300 or more people to monitor the presence of 29 per- and polyfluoroalkyl substances (PFAS) and lithium in drinking water supplies....